U.S. patent number 8,548,330 [Application Number 12/914,585] was granted by the patent office on 2013-10-01 for sectorization in distributed antenna systems, and related components and methods.
This patent grant is currently assigned to Corning Cable Systems LLC. The grantee listed for this patent is Igor Berlin, William P. Cune, Jason E. Greene, Michael Sauer, Gerald B. Schmidt. Invention is credited to Igor Berlin, William P. Cune, Jason E. Greene, Michael Sauer, Gerald B. Schmidt.
United States Patent |
8,548,330 |
Berlin , et al. |
October 1, 2013 |
Sectorization in distributed antenna systems, and related
components and methods
Abstract
Embodiments disclosed provide sectorization in distributed
antenna systems, and related components and methods. The antenna
units in the distributed antenna systems can be sectorized. In this
regard, one or more radio bands distributed by the distributed
antenna systems can be allocated to one or more sectors. The
antenna units in the distributed antenna systems are also allocated
to one or more sectors. In this manner, only radio frequency (RF)
communications signals in the radio band(s) allocated to given
sector(s) are distributed the antenna unit allocated to the same
sector(s). The bandwidth capacity of the antenna unit is split
among the radio band(s) allocated to sector(s) allocated to the
antenna unit. The sectorization of the radio band(s) and the
antenna units can be configured and/or altered based on capacity
needs for given radio bands in antenna coverage areas provide by
the antenna units.
Inventors: |
Berlin; Igor (Potomac, MD),
Cune; William P. (Charlotte, NC), Greene; Jason E.
(Hickory, NC), Sauer; Michael (Corning, NY), Schmidt;
Gerald B. (Painted Post, NY) |
Applicant: |
Name |
City |
State |
Country |
Type |
Berlin; Igor
Cune; William P.
Greene; Jason E.
Sauer; Michael
Schmidt; Gerald B. |
Potomac
Charlotte
Hickory
Corning
Painted Post |
MD
NC
NC
NY
NY |
US
US
US
US
US |
|
|
Assignee: |
Corning Cable Systems LLC
(Hickory, NC)
|
Family
ID: |
44908117 |
Appl.
No.: |
12/914,585 |
Filed: |
October 28, 2010 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20110268449 A1 |
Nov 3, 2011 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61330383 |
May 2, 2010 |
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61230463 |
Jul 31, 2009 |
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61230472 |
Jul 31, 2009 |
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Current U.S.
Class: |
398/115; 398/116;
340/2.22; 455/422.1; 398/79 |
Current CPC
Class: |
H04B
10/25753 (20130101); H04B 10/25752 (20130101); H04W
88/085 (20130101) |
Current International
Class: |
H04B
10/00 (20130101) |
Field of
Search: |
;398/79,115-117
;455/422.1-562.1 ;340/2.22 ;370/280-338 ;379/56.2 |
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|
Primary Examiner: Liu; Li
Attorney, Agent or Firm: Montgomery; C. Keith
Parent Case Text
RELATED APPLICATIONS
The present application is related to U.S. Provisional Patent
Application Ser. No. 61/330,383 filed on May 2, 2010 and entitled
"Optical Fiber-Based Distributed Communications Systems, and
Related Components and Methods," which is incorporated herein by
reference in its entirety.
The present application is also related to U.S. Provisional Patent
Application Ser. No. 61/230,463 filed on Jul. 31, 2009 and entitled
"Optical Fiber-Based Distributed Antenna Systems, Components, and
Related Methods for Calibration Thereof," which is incorporated
herein by reference in its entirety.
The present application is also related to U.S. Provisional Patent
Application Ser. No. 61/230,472 filed on Jul. 31, 2009 and entitled
"Optical Fiber-Based Distributed Antenna Systems, Components, and
Related Methods for Monitoring the Status Thereof," which is
incorporated herein by reference in its entirety.
Claims
What is claimed is:
1. An apparatus configured to distribute radio bands in one or more
sectors among a plurality of sectors in a distributed antenna
system, comprising: a plurality of radio interfaces each configured
to: split a received downlink electrical radio frequency (RF)
communications signal into a plurality of downlink electrical RF
communications signals; and control providing each of the split
plurality of downlink electrical RF communications signals to one
or more sectors among a plurality of sectors in a distributed
antenna system configured for the radio interface; and a plurality
of optical interfaces each configured to: receive the split
plurality of downlink electrical RF communications signals from the
plurality of radio interfaces; control for which sectors among the
plurality of sectors configured for the optical interface, the
received split plurality of downlink electrical RF communications
signals are provided to one or more remote antenna units (RAUs)
communicatively coupled to the optical interface; and convert the
received split plurality of downlink electrical RF communications
signals into a plurality of downlink optical RF communications
signals, wherein the plurality of optical interfaces are each
further configured to: split a received uplink optical RF
communications signal into a plurality of uplink optical RF
communications signals; control providing each of the split
plurality of uplink optical RF communications signals to the one or
more sectors among a plurality of sectors configured for the
optical interface; and convert the received split plurality of
uplink optical RF communications signals into a plurality of uplink
electrical RF communications signals; and the plurality of radio
interfaces are each further configured to: receive the plurality of
uplink electrical RF communications signals from the plurality of
optical interfaces; and control for which sectors among the
plurality of sectors configured for the radio interface the
received plurality of uplink electrical RF communications signals
are provided to one or more carriers communicatively coupled to the
radio interface.
2. The apparatus of claim 1, wherein each of the plurality of
optical interfaces is further configured to provide the plurality
of downlink optical RF communications signals to the one or more
RAUs.
3. The apparatus of claim 1, further comprising a downlink
distribution matrix configured to distribute the split plurality of
downlink electrical RF communications signals for the plurality of
sectors.
4. The apparatus of claim 1, wherein each of plurality of radio
interfaces is further configured to filter the received downlink
electrical RF communications signal in a single radio band.
5. The apparatus of claim 1, wherein each of the plurality of radio
interfaces further comprises a plurality of downlink sector
switches each assigned to a unique sector among a plurality of
sectors in the distributed antenna system, and each configured to:
receive a downlink electrical RF communications signal among the
split plurality of downlink electrical RF communications signals;
and control whether the received downlink electrical RF
communications signal is distributed to the unique sector assigned
to the downlink sector switch.
6. The apparatus of claim 1, wherein each of the plurality of
optical interfaces further comprises a plurality of downlink sector
switches each assigned to a unique sector among the plurality of
sectors in the distributed antenna system, and each configured to:
receive a downlink electrical RF communications signal among the
split plurality of downlink electrical RF communications signals
for the unique sector assigned to the downlink sector switch; and
control whether the received split downlink electrical RF
communications signal is distributed to the unique sector assigned
to the downlink sector switch.
7. The apparatus of claim 1, wherein each of the plurality of radio
interfaces further comprises a plurality of attenuators each
assigned to a sector among the plurality of sectors and configured
to control a power level for the assigned sector.
8. The apparatus of claim 1, further comprising a controller
configured to control for each of the plurality of radio interfaces
which of the one or more sectors among the plurality of sectors the
split plurality of downlink electrical RF communications signals
are provided.
9. The apparatus of claim 1, further comprising a controller
configured to control for each of the plurality of optical
interfaces which of the one or more sectors among the plurality of
sectors the split plurality of downlink electrical RF
communications signals are provided.
10. The apparatus of claim 1, further comprising a controller
configured to control sectorization for the plurality of radio
interfaces according to a sectorization configuration stored in a
sectorization table.
11. The apparatus of claim 10, wherein the sectorization table is
comprised of a sector activation entry and a corresponding power
level entry for each of the plurality of sectors for each of the
plurality of radio interfaces.
12. The apparatus of claim 1, further comprising at least one
expansion port coupled to a sector among the plurality of
sectors.
13. The apparatus of claim 12, further comprising at least one
additional plurality of optical interfaces coupled to the at least
one expansion port.
14. The apparatus of claim 1, further comprising an external
distribution matrix configured to distribute the received split
plurality of downlink electrical RF communications signals for the
plurality of sectors.
15. The apparatus of claim 1, wherein each of the plurality of
radio interfaces is further configured to provide the received
plurality of uplink electrical RF communications signals to the one
or more carriers.
16. The apparatus of claim 1, further comprising an uplink
distribution matrix configured to distribute the received split
plurality of uplink optical RF communications signals for the
plurality of sectors.
17. The apparatus of claim 1, wherein each of the plurality of
optical interfaces further comprises a plurality of uplink sector
switches each assigned to a unique sector among a plurality of
sectors in the distributed antenna system, and each configured to:
receive an uplink optical RF communications signal among the
plurality of uplink optical RF communications signals; and control
whether the received uplink optical RF communications signal is
distributed to the unique sector assigned to the uplink sector
switch.
18. The apparatus of claim 1, wherein each of the plurality of
radio interfaces further comprises a plurality of uplink sector
switches each assigned to a unique sector among the plurality of
sectors in the distributed antenna system, and each configured to:
receive an uplink electrical RF communications signal among the
plurality of uplink electrical RF communications signals for the
unique sector assigned to the uplink sector switch; and control
whether the uplink electrical RF communications signal is
distributed to the unique sector assigned to the uplink sector
switch.
19. The apparatus of claim 1, further comprising a controller
configured to control for each of the plurality of optical
interfaces which of the one or more sectors among the plurality of
sectors the split plurality of uplink optical RF communications
signals are provided.
20. The apparatus of claim 1, further comprising a controller
configured to control for each of the plurality of radio interfaces
which of the one or more sectors among the plurality of sectors the
plurality of uplink electrical RF communications signals from the
plurality of optical interfaces are provided.
21. A method of distributing radio bands in one or more sectors
among a plurality of sectors in a distributed antenna system,
comprising: splitting a received downlink electrical radio
frequency (RF) communications signal into a plurality of downlink
electrical RF communications signals; controlling providing each of
the split plurality of downlink electrical RF communications
signals to one or more sectors among a plurality of sectors in a
distributed antenna system; receiving the split plurality of
downlink electrical RF communications signals; controlling for
which sectors among the plurality of sectors, the received split
plurality of downlink electrical RF communications signals are
provided to one or more remote antenna units (RAUs)
communicatively; converting the received split plurality of
downlink electrical RF communications signals into a plurality of
downlink optical RF communications signals; splitting a received
uplink optical RF communications signal into a plurality of uplink
optical RF communication signals, controlling providing each of the
split plurality of uplink optical RF communications signals to the
one or more sectors among a plurality of sectors configured for the
optical interface; converting the received split plurality of
uplink optical RF communications signals into a plurality of uplink
electrical RF communications signals; receiving the plurality of
uplink electrical RF communications signals from the plurality of
optical interfaces; and controlling for which sectors among the
plurality of sectors configured for the radio interface, the
received plurality of uplink electrical RF communications signals
are provided to one or more carriers communicatively coupled to the
radio interface.
22. The method of claim 21, further comprising providing the
plurality of downlink optical RF communications signals to the one
or more RAUs.
23. The method of claim 21, further comprising distributing the
split plurality of downlink electrical RF communications signals
for the plurality of sectors in a distribution matrix.
24. The method of claim 21, further comprising controlling in a
controller for each of the plurality of radio interfaces which of
the one or more sectors among the plurality of sectors the split
plurality of downlink electrical RF communications signals are
provided.
25. The method of claim 21, further comprising controlling in a
controller for each of the plurality of optical interfaces which of
the one or more sectors among the plurality of sectors the split
plurality of downlink electrical RF communications signals are
provided.
26. The method of claim 21, further comprising controlling in a
controller for each of the plurality of optical interfaces which of
the one or more sectors among the plurality of sectors the split
plurality of uplink optical RF communications signals are
provided.
27. The method of claim 21, further comprising controlling in a
controller for each of the plurality of radio interfaces which of
the one or more sectors among the plurality of sectors the
plurality of uplink electrical RF communications signals from the
plurality of optical interfaces are provided.
28. The method of claim 21, wherein the at least one RAU is
comprised of a plurality of RAUs, and further comprising assigning
at least two of the plurality of RAUs to a MIMO communication
configuration.
29. The method of claim 28, further comprising assigning the at
least two of the plurality of RAUs in the MIMO configuration to the
same sector among the plurality of sectors.
Description
BACKGROUND
1. Field of the Disclosure
The technology of the disclosure relates to distributed antenna
systems for distributing radio frequency (RF) signals to remote
antenna units.
2. Technical Background
Wireless communication is rapidly growing, with ever-increasing
demands for high-speed mobile data communication. As an example,
so-called "wireless fidelity" or "WiFi" systems and wireless local
area networks (WLANs) are being deployed in many different types of
areas (e.g., coffee shops, airports, libraries, etc.). Distributed
antenna systems communicate with wireless devices called "clients,"
which must reside within the wireless range or "cell coverage area"
in order to communicate with an access point device.
One approach to deploying a distributed antenna system involves the
use of radio frequency (RF) antenna coverage areas, also referred
to as "antenna coverage areas." The antenna coverage areas are
provided by remote antenna units in the distributed antenna system.
Remote antenna units can provide antenna coverage areas having
radii in the range from a few meters up to twenty (20) meters as an
example. If the antenna coverage areas provided each cover a small
area, there are typically only a few users (clients) per antenna
coverage area. This allows for minimizing the amount of RF
bandwidth shared among the wireless system users. It may be
desirable to provide antenna coverage areas in a building or other
facility to provide indoor distributed antenna system access to
clients within the building or facility. It may also be desirable
to employ optical fiber to distribute RF communications signals to
provide an optical fiber-based distributed antenna system.
Distribution of RF communications signals over optical fiber can
include Radio-over-Fiber (RoF) distribution. Benefits of optical
fiber include increased bandwidth.
Remote antenna units in a distributed antenna system can be
configured to distribute RF communication signals in multiple radio
bands (i.e., frequencies or ranges of frequencies), as opposed to a
single radio band. Distributing RF communications signals in
multiple radio bands in an antenna coverage area increases
flexibility of the distributed antenna system. In this scenario,
client devices configured to communicate in different radio bands
can be supported in a given antenna coverage area provided by the
remote antenna unit. However, providing remote antenna units that
support multiple radio bands can also limit capacity in the
distributed antenna system. The bandwidth of the remote antenna
unit is split among the multiple radio bands thus reducing the
capacity of each supported radio band in a given antenna coverage
area.
To offset a reduction in capacity in remote antenna units
supporting multiple radio bands, additional remote antenna units
could be provided. The remote antenna units could be co-located and
each configured to support only one of the radio bands. However,
providing additional remote antenna units increases the cost of the
distributed antenna system. Further, additional head-end equipment
may be required to be deployed to support the additional remote
antenna units. Providing additional remote antenna units to provide
additional capacity may be delayed after initial installation and
provided as needed, but higher installation costs may be associated
with retrofitting an existing installation with additional remote
antenna units.
SUMMARY OF THE DETAILED DESCRIPTION
Embodiments disclosed in the detailed description include providing
sectorization in distributed antenna systems, and related
components and methods. As one non-limiting example, the
distributed antenna systems may be optical fiber-based distributed
antenna systems. The antenna units in the distributed antenna
systems can be sectorized. In this regard, one or more radio bands
distributed by the distributed antenna systems can be allocated to
one or more sectors. The antenna units in the distributed antenna
systems are also allocated to one or more sectors. In this manner,
only radio frequency (RF) communications signals in the radio
band(s) allocated to given sector(s) are distributed to the antenna
unit allocated to the same sector(s). The bandwidth capacity of the
antenna unit is split among the radio band(s) allocated to
sector(s) allocated to the antenna unit. The sectorization of the
radio band(s) and the antenna units can be configured and/or
altered based on capacity needs for given radio bands in antenna
coverage areas provide by the antenna units.
In one embodiment, a head-end apparatus or equipment configured to
distribute radio bands in one or more sectors among a plurality of
sectors in a distributed antenna system is provided. The head end
equipment includes a plurality of radio interfaces each configured
to split a received downlink electrical RF communications signal
into a plurality of downlink electrical RF communications signals.
Each of the plurality of radio interfaces is also configured to
control providing each of the split plurality of downlink
electrical RF communications signals to one or more sectors among a
plurality of sectors in a distributed antenna system configured for
the radio interface. A plurality of optical interfaces is also
provided and each configured to receive the split plurality of
downlink electrical RF communications signals from the plurality of
radio interfaces. Each of the plurality of optical interfaces is
also configured to control for which sectors among the plurality of
sectors configured for the optical interface the received split
plurality of downlink electrical RF communications signals are
provided to one or more remote antenna units (RAUs) communicatively
coupled to the optical interface. Each of the plurality of optical
interfaces is also configured to convert the received split
plurality of downlink electrical RF communications signals into a
plurality of downlink optical RF communications signals.
The head end equipment may also include components to sectorize
uplink RF communications signals as well. In this regard, in
another embodiment, each of the plurality of optical interfaces
provided in the head end equipment is further configured to split a
received uplink optical RF communications signal into a plurality
of uplink optical RF communications signals. Each of the plurality
of optical interfaces is also configured to control providing each
of the split plurality of uplink optical RF communications signals
to the one or more sectors among a plurality of sectors configured
for the optical interface. Each of the plurality of optical
interfaces is also configured to convert the received split
plurality of uplink optical RF communications signals into a
plurality of uplink electrical RF communications signals. Each of
the plurality of radio interfaces provided in the head end
equipment is further configured to receive the plurality of uplink
electrical RF communications signals from the plurality of optical
interfaces. Each of the plurality of radio interfaces is also
configured to control for which sectors among the plurality of
sectors configured for the radio interface the received plurality
of uplink electrical RF communications signals are provided to one
or more carriers communicatively coupled to the radio
interface.
In another embodiment, a method of distributing radio bands in one
or more sectors among a plurality of sectors in a distributed
antenna system is provided. The method includes splitting a
received downlink electrical RF communications signal into a
plurality of downlink electrical RF communications signals. The
method also includes providing each of the split plurality of
downlink electrical RF communications signals to one or more
sectors among a plurality of sectors in a distributed antenna
system. The method also includes receiving the split plurality of
downlink electrical RF communications signals. The method also
includes controlling for which sectors among the plurality of
sectors the received split plurality of downlink electrical RF
communications signals are provided to one or more RAUs
communicatively. The method also includes converting the received
split plurality of downlink electrical RF communications signals
into a plurality of downlink optical RF communications signals.
In another embodiment, a radio interface configured to distribute
radio bands in unique sectors among a plurality of sectors in a
distributed antenna system is provided. The radio interface
includes a downlink interface configured to receive a downlink RF
communications signal. The radio interface also includes a downlink
splitter configured to split the downlink RF communications signal
into a plurality of downlink RF communications signals. The radio
interface also includes a plurality of downlink sector switches
each assigned to a unique sector among a plurality of sectors in a
distributed antenna system. Each of the plurality of downlink
sector switches is configured to receive a downlink RF
communications signal among the plurality of downlink RF
communications signals from the downlink splitter, and control
whether the received downlink RF communications signal is
distributed to the unique sector assigned to the sector switch. The
radio interface may also include components to sectorize uplink RF
communications signals as well.
In another embodiment, an optical interface configured to
distribute radio bands in unique sectors among a plurality of
sectors in a distributed antenna system is provided. The optical
interface includes a downlink interface configured to receive a
plurality of downlink electrical RF communications signals each
assigned to a unique sector among a plurality of sectors in a
distributed antenna system. The optical interface also includes a
plurality of downlink sector switches each assigned to a unique
sector in the distributed antenna system. Each of the plurality of
downlink sector switches is configured to receive a downlink
electrical RF communications signal among the plurality of downlink
electrical RF communications signals for the unique sector assigned
to the sector switch. Each of the plurality of downlink sector
switches is also configured to control whether the received
downlink electrical RF communications signal is distributed to the
unique sector assigned to the sector switch. A plurality of
downlink electrical-to-optical (E/O) converters are provided in the
optical interface and each configured to receive the downlink
electrical RF communications signal from a sector switch among the
plurality of sector switches, and convert the received downlink
electrical RF communications signal into a downlink optical RF
communications signal. The optical interface may also include
components to sectorize uplink RF communications signals as
well.
Additional features and advantages will be set forth in the
detailed description which follows, and in part will be readily
apparent to those skilled in the art from that description or
recognized by practicing the embodiments as described herein,
including the detailed description that follows, the claims, as
well as the appended drawings.
It is to be understood that both the foregoing general description
and the following detailed description present embodiments, and are
intended to provide an overview or framework for understanding the
nature and character of the disclosure. The accompanying drawings
are included to provide a further understanding, and are
incorporated into and constitute a part of this specification. The
drawings illustrate various embodiments, and together with the
description serve to explain the principles and operation of the
concepts disclosed.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a schematic diagram of an exemplary optical fiber-based
distributed antenna system;
FIG. 2 is a more detailed schematic diagram of exemplary head end
equipment and a remote antenna unit (RAU) that can be deployed in
the optical fiber-based distributed antenna system of FIG. 1;
FIG. 3 is a partially schematic cut-away diagram of an exemplary
building infrastructure in which the optical fiber-based
distributed antenna system in FIG. 1 can be employed;
FIG. 4 is an schematic diagram illustrating exemplary sectorization
in a distributed antenna system;
FIG. 5 is a schematic diagram of another exemplary optical
fiber-based distributed antenna system;
FIG. 6 is a schematic diagram of exemplary head end equipment
provided in a distributed antenna system supporting configurable
sectorization in the distributed antenna system;
FIG. 7 is an exemplary sectorization table provided in head end
equipment to store a default and/or user-configured sectorization
for a distributed antenna system;
FIG. 8 is a schematic diagram of exemplary head end equipment
provided in a distributed antenna system and configured with
expansion ports to support additional remote antenna units, wherein
one expansion port supports an optical interface unit (OIU)
supporting a single sector;
FIG. 9 is a schematic diagram of exemplary head end equipment
provided in a distributed antenna system and configured with
expansion ports to support additional remote antenna units, wherein
multiple expansion ports support an OIU supporting multiple
sectors;
FIG. 10 is a schematic diagram of an exemplary radio distribution
matrix provided for a head end equipment to allow multiple carriers
to utilize common optical interface modules (OIMs) and RAUs to
distribute communications signals in a distributed antenna
system
FIG. 11 is a schematic diagram of providing an expanded number of
sectors in a distributed antenna system; and
FIG. 12 is a schematic diagram of exemplary head end equipment
provided in a distributed antenna system supporting sectorization
and multiple-input, multiple-output (MIMO) processing in a
distributed antenna system.
DETAILED DESCRIPTION
Reference will now be made in detail to the embodiments, examples
of which are illustrated in the accompanying drawings, in which
some, but not all embodiments are shown. Indeed, the concepts may
be embodied in many different forms and should not be construed as
limiting herein; rather, these embodiments are provided so that
this disclosure will satisfy applicable legal requirements.
Whenever possible, like reference numbers will be used to refer to
like components or parts.
Embodiments disclosed in the detailed description include providing
sectorization in distributed antenna systems, and related
components and methods. As one non-limiting example, the
distributed antenna systems may be optical fiber-based distributed
antenna systems. The antenna units in the distributed antenna
systems can be sectorized. In this regard, one or more radio bands
distributed by the distributed antenna systems can be allocated to
one or more sectors. The antenna units in the distributed antenna
systems are also allocated to one or more sectors. In this manner,
only radio frequency (RF) communications signals in the radio
band(s) allocated to given sector(s) are distributed to the antenna
unit allocated to the same sector(s). The bandwidth capacity of the
antenna unit is split among the radio band(s) allocated to
sector(s) allocated to the antenna unit. The sectorization of the
radio band(s) and the antenna units can be configured and/or
altered based on capacity needs for given radio bands in antenna
coverage areas provide by the antenna units.
Before discussing distributed antenna systems and related
components and methods that support sectorization starting at FIG.
4, FIGS. 1-3 are provided and first discussed below. FIGS. 1-3
provide examples of distributed antenna systems that do not include
sectorization support, but can be configured to provide
sectorization support, including according to the embodiments
described herein.
FIG. 1 is a schematic diagram of an embodiment of an optical
fiber-based distributed antenna system. In this embodiment, the
system is an optical fiber-based distributed antenna system 10 that
is configured to create one or more antenna coverage areas for
establishing communications with wireless client devices located in
the RF range of the antenna coverage areas. The optical fiber-based
distributed antenna system 10 provides RF communications services
(e.g., cellular services). In this embodiment, the optical
fiber-based distributed antenna system 10 includes head end
equipment in the form of a head-end unit (HEU) 12, one or more
remote antenna units (RAUs) 14, and an optical fiber 16 that
optically couples the HEU 12 to the RAU 14 in this example. The HEU
12 is configured to receive communications over downlink electrical
RF communications signals 18D from a source or sources, such as a
network or carrier as examples, and provide such communications to
the RAU 14. The HEU 12 is also configured to return communications
received from the RAU 14, via uplink electrical RF communications
signals 18U, back to the source or sources. In this regard in this
embodiment, the optical fiber 16 includes at least one downlink
optical fiber 16D to carry signals communicated from the HEU 12 to
the RAU 14 and at least one uplink optical fiber 16U to carry
signals communicated from the RAU 14 back to the HEU 12. One
downlink optical fiber 16D and one uplink optical fiber 16U could
be provided to support multiple channels each using
wavelength-division multiplexing (WDM), as discussed in U.S. patent
application Ser. No. 12/892,424 entitled "Providing Digital Data
Services in Optical Fiber-Based Distributed Radio Frequency (RF)
Communications Systems, And Related Components and Methods,"
incorporated herein by reference in its entirety. Other options for
WDM and frequency-division multiplexing (FDM) are also disclosed in
U.S. patent application Ser. No. 12/892,424, any of which can be
employed in any of the embodiments disclosed herein.
The optical fiber-based distributed antenna system 10 has an
antenna coverage area 20 that can be substantially centered about
the RAU 14. The antenna coverage area 20 of the RAU 14 forms an RF
coverage area 21. The HEU 12 is adapted to perform or to facilitate
any one of a number of wireless applications, including but not
limited to Radio-over-Fiber (RoF), radio frequency identification
(RFID), wireless local-area network (WLAN) communication, public
safety, cellular, telemetry, and other mobile or fixed services.
Shown within the antenna coverage area 20 is a client device 24 in
the form of a mobile device as an example, which may be a cellular
telephone as an example. The client device 24 can be any device
that is capable of receiving RF communication signals. The client
device 24 includes an antenna 26 (e.g., a wireless card) adapted to
receive and/or send electromagnetic RF communications signals.
With continuing reference to FIG. 1, to communicate the electrical
RF communications signals over the downlink optical fiber 16D to
the RAU 14, to in turn be communicated to the client device 24 in
the antenna coverage area 20 formed by the RAU 14, the HEU 12
includes an electrical-to-optical (E/O) converter 28. The E/O
converter 28 converts the downlink electrical RF communications
signals 18D to downlink optical RF communications signals 22D to be
communicated over the downlink optical fiber 16D. The RAU 14
includes an optical-to-electrical (O/E) converter 30 to convert
received downlink optical RF communications signals 22D back to
electrical RF communications signals to be communicated wirelessly
through an antenna 32 of the RAU 14 to client devices 24 located in
the antenna coverage area 20.
Similarly, the antenna 32 is also configured to receive wireless RF
communications from client devices 24 in the antenna coverage area
20. In this regard, the antenna 32 receives wireless RF
communications from client devices 24 and communicates electrical
RF communications signals representing the wireless RF
communications to an E/O converter 34 in the RAU 14. The E/O
converter 34 converts the electrical RF communications signals into
uplink optical RF communications signals 22U to be communicated
over the uplink optical fiber 16U. An O/E converter 36 provided in
the HEU 12 converts the uplink optical RF communications signals
22U into uplink electrical RF communications signals, which can
then be communicated as uplink electrical RF communications signals
18U back to a network or other source. The HEU 12 in this
embodiment is not able to distinguish the location of the client
devices 24 in this embodiment. The client device 24 could be in the
range of any antenna coverage area 20 formed by an RAU 14.
FIG. 2 is a more detailed schematic diagram of the exemplary
optical fiber-based distributed antenna system 10 of FIG. 1 that
provides electrical RF service signals for a particular RF service
or application. In an exemplary embodiment, the HEU 12 includes a
service unit 37 that provides electrical RF service signals by
passing (or conditioning and then passing) such signals from one or
more outside networks 38 via a network link 39. In a particular
example embodiment, this includes providing WLAN signal
distribution as specified in the Institute of Electrical and
Electronics Engineers (IEEE) 802.11 standard, i.e., in the
frequency range from 2.4 to 2.5 GigaHertz (GHz) and from 5.0 to 6.0
GHz. Any other electrical RF communications signal frequencies are
possible. In another exemplary embodiment, the service unit 37
provides electrical RF service signals by generating the signals
directly. In another exemplary embodiment, the service unit 37
coordinates the delivery of the electrical RF service signals
between client devices 24 within the antenna coverage area 20.
With continuing reference to FIG. 2, the service unit 37 is
electrically coupled to the E/O converter 28 that receives the
downlink electrical RF communications signals 18D from the service
unit 37 and converts them to corresponding downlink optical RF
communications signals 22D. In an exemplary embodiment, the E/O
converter 28 includes a laser suitable for delivering sufficient
dynamic range for the RoF applications described herein, and
optionally includes a laser driver/amplifier electrically coupled
to the laser. Examples of suitable lasers for the E/O converter 28
include, but are not limited to, laser diodes, distributed feedback
(DFB) lasers, Fabry-Perot (FP) lasers, and vertical cavity surface
emitting lasers (VCSELs).
With continuing reference to FIG. 2, the HEU 12 also includes the
O/E converter 36, which is electrically coupled to the service unit
37. The O/E converter 36 receives the uplink optical RF
communications signals 22U and converts them to corresponding
uplink electrical RF communications signals 18U. In an example
embodiment, the O/E converter 36 is a photodetector, or a
photodetector electrically coupled to a linear amplifier. The E/O
converter 28 and the O/E converter 36 constitute a "converter pair"
35, as illustrated in FIG. 2.
In accordance with an exemplary embodiment, the service unit 37 in
the HEU 12 can include an RF communications signal conditioner unit
40 for conditioning the downlink electrical RF communications
signals 18D and the uplink electrical RF communications signals
18U, respectively. The service unit 37 can include a digital signal
processing unit ("digital signal processor") 42 for providing to
the RF communications signal conditioner unit 40 an electrical
signal that is modulated onto an RF carrier to generate a desired
downlink electrical RF communications signal 18D. The digital
signal processor 42 is also configured to process a demodulation
signal provided by the demodulation of the uplink electrical RF
communications signal 18U by the RF communications signal
conditioner unit 40. The service unit 37 in the HEU 12 can also
include an optional central processing unit (CPU) 44 for processing
data and otherwise performing logic and computing operations, and a
memory unit 46 for storing data, such as data to be transmitted
over a WLAN or other network for example.
With continuing reference to FIG. 2, the RAU 14 also includes a
converter pair 48 comprising the O/E converter 30 and the E/O
converter 34. The O/E converter 30 converts the received downlink
optical RF communications signals 22D from the HEU 12 back into
downlink electrical RF communications signals 50D. The E/O
converter 34 converts uplink electrical RF communications signals
50U received from the client device 24 into the uplink optical RF
communications signals 22U to be communicated to the HEU 12. The
O/E converter 30 and the E/O converter 34 are electrically coupled
to the antenna 32 via an RF signal-directing element 52, such as a
circulator for example. The RF signal-directing element 52 serves
to direct the downlink electrical RF communications signals 50D and
the uplink electrical RF communications signals 50U, as discussed
below. In accordance with an exemplary embodiment, the antenna 32
can include one or more patch antennas, such as disclosed in U.S.
patent application Ser. No. 11/504,999, filed Aug. 16, 2006
entitled "Radio-over-Fiber Transponder With A Dual-Band Patch
Antenna System," and U.S. patent application Ser. No. 11/451,553,
filed Jun. 12, 2006 entitled "Centralized Optical Fiber-based
Wireless Picocellular Systems and Methods," both of which are
incorporated herein by reference in their entireties.
With continuing reference to FIG. 2, the optical fiber-based
distributed antenna system 10 also includes a power supply 54 that
generates an electrical power signal 56. The power supply 54 is
electrically coupled to the HEU 12 for powering the power-consuming
elements therein. In an exemplary embodiment, an electrical power
line 58 runs through the HEU 12 and over to the RAU 14 to power the
O/E converter 30 and the E/O converter 34 in the converter pair 48,
the optional RF signal-directing element 52 (unless the RF
signal-directing element 52 is a passive device such as a
circulator for example), and any other power-consuming elements
provided. In an exemplary embodiment, the electrical power line 58
includes two wires 60 and 62 that carry a single voltage and that
are electrically coupled to a DC power converter 64 at the RAU 14.
The DC power converter 64 is electrically coupled to the O/E
converter 30 and the E/O converter 34 in the converter pair 48, and
changes the voltage or levels of the electrical power signal 56 to
the power level(s) required by the power-consuming components in
the RAU 14. In an exemplary embodiment, the DC power converter 64
is either a DC/DC power converter or an AC/DC power converter,
depending on the type of electrical power signal 56 carried by the
electrical power line 58. In another example embodiment, the
electrical power line 58 (dashed line) runs directly from the power
supply 54 to the RAU 14 rather than from or through the HEU 12. In
another example embodiment, the electrical power line 58 includes
more than two wires and carries multiple voltages.
To provide further exemplary illustration of how an optical
fiber-based distributed antenna system can be deployed indoors,
FIG. 3 is provided. FIG. 3 is a partially schematic cut-away
diagram of a building infrastructure 70 employing an optical
fiber-based distributed antenna system. The system may be the
optical fiber-based distributed antenna system 10 of FIGS. 1 and 2.
The building infrastructure 70 generally represents any type of
building in which the optical fiber-based distributed antenna
system 10 can be deployed. As previously discussed with regard to
FIGS. 1 and 2, the optical fiber-based distributed antenna system
10 incorporates the HEU 12 to provide various types of
communication services to coverage areas within the building
infrastructure 70, as an example. For example, as discussed in more
detail below, the optical fiber-based distributed antenna system 10
in this embodiment is configured to receive wireless RF
communications signals and convert the RF communications signals
into RoF signals to be communicated over the optical fiber 16 to
multiple RAUs 14. The optical fiber-based distributed antenna
system 10 in this embodiment can be, for example, an indoor
distributed antenna system (IDAS) to provide wireless service
inside the building infrastructure 70. These wireless signals can
include, but are not limited to, cellular service, wireless
services such as RFID tracking, Wireless Fidelity (WiFi), local
area network (LAN), WLAN, and combinations thereof, as
examples.
With continuing reference to FIG. 3, the building infrastructure 70
in this embodiment includes a first (ground) floor 72, a second
floor 74, and a third floor 76. The floors 72, 74, 76 are serviced
by the HEU 12 through a main distribution frame 78 to provide
antenna coverage areas 80 in the building infrastructure 70. Only
the ceilings of the floors 72, 74, 76 are shown in FIG. 3 for
simplicity of illustration. In the example embodiment, a main cable
82 has a number of different sections that facilitate the placement
of a large number of RAUs 14 in the building infrastructure 70.
Each RAU 14 in turn services its own coverage area in the antenna
coverage areas 80. The main cable 82 can include, for example, a
riser cable 84 that carries all of the downlink and uplink optical
fibers 16D, 16U to and from the HEU 12. The riser cable 84 may be
routed through an interconnect unit (ICU) 85. The ICU 85 may be
provided as part of or separate from the power supply 54 in FIG. 2.
The ICU 85 may also be configured to provide power to the RAUs 14
via the electrical power line 58, as illustrated in FIG. 2 and
discussed above, provided inside an array cable 87, or tail cable
or home-run tether cable as other examples, and distributed with
the downlink and uplink optical fibers 16D, 16U to the RAUs 14. The
main cable 82 can include one or more multi-cable (MC) connectors
adapted to connect select downlink and uplink optical fibers 16D,
16U, along with an electrical power line, to a number of optical
fiber cables 86.
The main cable 82 enables the multiple optical fiber cables 86 to
be distributed throughout the building infrastructure 70 (e.g.,
fixed to the ceilings or other support surfaces of each floor 72,
74, 76) to provide the antenna coverage areas 80 for the first,
second and third floors 72, 74 and 76. In an example embodiment,
the HEU 12 is located within the building infrastructure 70 (e.g.,
in a closet or control room), while in another example embodiment,
the HEU 12 may be located outside of the building infrastructure 70
at a remote location. A base transceiver station (BTS) 88, which
may be provided by a second party such as a cellular service
provider, is connected to the HEU 12, and can be co-located or
located remotely from the HEU 12. A BTS is any station or source
that provides an input signal to the HEU 12 and can receive a
return signal from the HEU 12. In a typical cellular system, for
example, a plurality of BTSs are deployed at a plurality of remote
locations to provide wireless telephone coverage. Each BTS serves a
corresponding cell and when a mobile station enters the cell, the
BTS communicates with the mobile station. Each BTS can include at
least one radio transceiver for enabling communication with one or
more subscriber units operating within the associated cell.
Alternatively, radio input could be provided by a repeater or
picocell as other examples.
The optical fiber-based distributed antenna system 10 in FIGS. 1-3
and described above provides point-to-point communications between
the HEU 12 and the RAU 14. Each RAU 14 communicates with the HEU 12
over a distinct downlink and uplink optical fiber pair to provide
the point-to-point communications. Whenever an RAU 14 is installed
in the optical fiber-based distributed antenna system 10, the RAU
14 is connected to a distinct downlink and uplink optical fiber
pair connected to the HEU 12. The downlink and uplink optical
fibers may be provided in the optical fiber 16. Multiple downlink
and uplink optical fiber pairs can be provided in a fiber optic
cable to service multiple RAUs 14 from a common fiber optic cable.
For example, with reference to FIG. 3, RAUs 14 installed on a given
floor 72, 74, or 76 may be serviced from the same optical fiber 16.
In this regard, the optical fiber 16 may have multiple nodes where
distinct downlink and uplink optical fiber pairs can be connected
to a given RAU 14.
It may be desirable to provide an optical fiber-based distributed
antenna system that can support a wide variety of radio sources.
For example, it may be desired to provide an optical fiber-based
distributed antenna system that can support various radio types and
sources, including but not limited to Long Term Evolution (LTE), US
Cellular (CELL), Global System for Mobile Communications (GSM),
Code Division Multiple Access (CDMA), Time Division Multiple Access
(TDMA), Advanced Wireless Services (AWS), iDEN (e.g., 800 MegaHertz
(MHz), 900 MHz, and 1.5 GHz), etc. These radios sources can range
from 400 MHz to 2700 MHz as an example. To support a radio source,
the HEU must contain lasers that are capable of modulating the
radio signal into optical RF communications signals at the
frequency of the radio signal for transmission over optical fiber.
Likewise, lasers must be provided to convert the optical RF
communications signals back into electrical RF communications
signals at the frequencies of the radio band supported. It is
costly to provide different conversion lasers for all possible
radio sources that may be desired to be supported by an optical
fiber-based distributed antenna system.
In this regard, embodiments disclosed herein include providing
sectorization in distributed antenna systems, and related
components and methods. As one non-limiting example, the
distributed antenna systems may be optical fiber-based distributed
antenna systems. The antenna units in the distributed antenna
systems can be sectorized. In this regard, one or more radio bands
distributed by the distributed antenna systems can be allocated to
one or more sectors. The antenna units in the distributed antenna
systems are also allocated to one or more sectors. In this manner,
only radio frequency (RF) communications signals in the radio
band(s) allocated to given sector(s) are distributed the antenna
unit allocated to the same sector(s). The bandwidth capacity of the
antenna unit is split among the radio band(s) allocated to
sector(s) allocated to the antenna unit. The sectorization of the
radio band(s) and the antenna units can be configured and/or
altered based on capacity needs for given radio bands in antenna
coverage areas provide by the antenna units.
FIG. 4 is a schematic diagram to illustrate an example of providing
sectorization in a distributed antenna system. In this regard as
illustrated in FIG. 4, a distributed antenna system 90 is provided.
The distributed antenna system 90 can be, without limitation, an
optical fiber-based distributed antenna system. The distributed
antenna system 90 can include the exemplary distributed antenna
systems discussed above in FIGS. 1-3, or any of the other exemplary
distributed antenna systems disclosed herein. The distributed
antenna system includes an HEU 92 that is configured to receive and
distribute RF communication signals in a plurality of radio bands
or frequencies R.sub.1-R.sub.N. The HEU 92 is configured to
distribute the radio bands R.sub.1-R.sub.N to a plurality of RAUs
94 communicatively coupled to the HEU 94. For example, the RAUs 94
may be distributed in multiple floors 96A-96D in a building 98 or
other facility. The HEU 92 is configured to sectorize the RAUs 94
into different sectors. One or more of the radio bands
R.sub.1-R.sub.N can be allocated to each sector.
In this example, the RAUs 94 are allocated to one of three (3)
sectors. For example, RAUs 94(1) allocated to a first sector are
shown as circle symbols in FIG. 4. RAUs 94(2) allocated to a second
sector are shown as triangle symbols in FIG. 4. RAUs 94(3)
allocated to a third sector are shown as square symbols in FIG. 4.
The RAUs 94 are allocated to one or more sectors as a method of
controlling how many radio bands R.sub.1-R.sub.N are supported by
the RAUs 94 and in which the bandwidth of the RAUs 94 are split. As
capacity and performance requirements or needs change for the
distributed antenna system 90, the sector allocated to particular
RAUs 94 can be changed and/or the radio bands R.sub.1-R.sub.N
allocated to a given sector can be changed. The sector allocated to
a given RAU 94 can also be changed or reconfigured flexibly and
seamlessly to change how the bandwidth of the RAUs 94 is split
among allocated radio bands R.sub.1-R.sub.N. Deployment of
additional RAUs 94 to change the amount of bandwidth dedicated to
particular radio bands R.sub.1-R.sub.N is not required.
FIG. 5 is a schematic diagram of another exemplary distributed
antenna system 100 that can support sectorization. In this
embodiment, the distributed antenna system 100 is an optical
fiber-based distributed antenna system comprised of three main
components. One or more radio interfaces provided in the form of
radio interface modules (RIMs) 102(1)-102(M) in this embodiment are
provided in head end equipment 104 to receive and process downlink
electrical RF communications signals 106(1)-106(R) prior to optical
conversion into downlink optical RF communications signals. The
processing of the downlink electrical RF communications signals
106(1)-106(R) can include any of the procession previously
described above in the HEU 12 in FIG. 2. The notations "1-R" and
"1-M" indicate that any number of the referenced component, 1-R and
1-M, respectively, may be provided. As will be described in more
detail below, the head end equipment 104 in this embodiment is
configured to accept a plurality of RIMs 102(1)-102(M) as modular
components that can be easily installed and removed or replaced in
the HEU 104. In one embodiment, the head end equipment 104 is
configured to support up to four (4) RIMs 102(1)-102(M) as an
example.
Each RIM 102(1)-102(M) can be designed to support a particular type
of radio source or range of radio sources (i.e., frequencies) to
provide flexibility in configuring the head end equipment 104 and
optical fiber-based distributed antenna system 100 to support the
desired radio sources. For example, one RIM 102 may be configured
to support the Personal Communication Services (PCS) radio band.
Another RIM 102 may be configured to support the Long Term
Evolution (LTE) 700 radio band. In this example, by inclusion of
these RIMs 102, the head end equipment 104 would be configured to
support and distribute RF communications signals on both PCS and
LTE 700 radio bands. RIMs 102 may be provided in the head end
equipment 104 that support any other radio bands desired, including
but not limited to PCS, LTE, CELL, GSM, CDMA, CDMA2000, TDMA, AWS,
iDEN (e.g., 800 MHz, 900 MHz, and 1.5 GHz), Enhanced Data GSM
Environment, (EDGE), Evolution-Data Optimized (EV-DO), 1xRTT (i.e.,
CDMA2000 1X (IS-2000)), High Speed Packet Access (HSPA), 3GGP1,
3GGP2, and Cellular Digital Packet Data (CDPD). More specific
examples include, but are not limited to, radio bands between
400-2700 MHz including but not limited to 700 MHz (LTE), 698-716
MHz, 728-757 MHz, 776-787 MHz, 806-824 MHz, 824-849 MHz (US
Cellular), 851-869 MHz, 869-894 MHz (US Cellular), 880-915 MHz (EU
R), 925-960 MHz (TTE), 1930-1990 MHz (US PCS), 2110-2155 MHz (US
AWS), 925-960 MHz (GSM 900), 1710-1755 MHz, 1850-1915 MHz,
1805-1880 MHz (GSM 1800), 1920-1995 MHz, and 2110-2170 MHz (GSM
2100).
The downlink electrical RF communications signals 106(1)-106(R) are
provided to a plurality of optical interfaces provided in the form
of optical interface modules (OIMs) 108(1)-108(N) in this
embodiment to convert the downlink electrical RF communications
signals 106(1)-106(N) into downlink optical signals 110(1)-110(R).
The notation "1-N" indicates that any number of the referenced
component 1-N may be provided. One downlink optical fiber 113D and
one uplink optical fiber 113U could be provided to support multiple
channels each using WDM, as discussed in U.S. patent application
Ser. No. 12/892,424 previously referenced above. Other options for
WDM and FDM are also disclosed in U.S. patent application Ser. No.
12/892,424, any of which can be employed in any of the embodiments
disclosed herein.
In this embodiment, the OIMs 108(1)-108(N) are provided in a common
housing provided for the head end equipment 104 with the RIMs
102(1)-102(M). Alternatively, the OIMs 108(1)-108(N) could be
located separately from the RIMs 102(1)-102(M). The OIMs 108 may be
configured to provide one or more optical interface components
(OICs) that contain O/E and E/O converters, as will be described in
more detail below. The OIMs 108 support the radio bands that can be
provided by the RIMs 102, including the examples previously
described above. Thus, in this embodiment, the OIMs 108 may support
a radio band range from 400 MHz to 2700 MHz, as an example, so
providing different types or models of OIMs 108 for narrower radio
bands to support possibilities for different radio band supported
RIMs 102 provided in the head end equipment 104 is not required.
Further, as an example, the OIMs 108s may be optimized for
sub-bands within the 400 MHz to 2700 MHz frequency range, such as
400-700 MHz, 700 MHz-1 GHz, 1 GHz-1.6 GHz, and 1.6 GHz-2.7 GHz, as
examples.
The OIMs 108(1)-108(N) each include E/O converters to convert the
downlink electrical RF communications signals 106(1)-106(R) to
downlink optical signals 110(1)-110(R). The downlink optical
signals 110(1)-110(R) are communicated over downlink optical
fiber(s) 113D to a plurality of RAUs 112(1)-112(P). The notation
"1-P" indicates that any number of the referenced component 1-P may
be provided. O-E converters provided in the RAUs 112(1)-112(P)
convert the downlink optical signals 110(1)-110(R) back into
downlink electrical RF communications signals 104(1)-104(R), which
are provided over links 114(1)-114(P) coupled to antennas
116(1)-116(P) in the RAUs 112(1)-112(P) to client devices in the
reception range of the antennas 116(1)-116(P).
E/O converters are also provided in the RAUs 112(1)-112(P) to
convert uplink electrical RF communications signals received from
client devices through the antennas 116(1)-116(P) into uplink
optical signals 118(1)-118(R) to be communicated over uplink
optical fibers 113U to the OIMs 108(1)-108(N). The OIMs
108(1)-108(N) include O/E converters that convert the uplink
optical signals 118(1)-118(R) into uplink electrical RF
communications signals 120(1)-120(R) that are processed by the RIMs
102(1)-102(M) and provided as uplink electrical RF communications
signals 122(1)-122(R).
FIG. 6 is a schematic diagram illustrating more detail regarding
the internal components of the head end equipment 104 in FIG. 5
supporting sectorization of RAUs 112 to particular radio bands.
Each RIM 102(1)-102(M) includes one or more filters 124 that are
configured to filter out the undesired radio bands for the RIM 102
from the received downlink electrical RF communications signals
106(1)-106(R) and uplink electrical RF communications signals
122(1)-122(R). Although multiple downlink electrical RF
communications signals 106(1)-106(R) and uplink electrical RF
communications signals 122(1)-122(R) are shown, it is understood
that only a subset of these signals may be distributed by each RIM
102 according to the filters 124 and radio band of the received
uplink electrical RF communications signals 120(1)-120(R) from the
OIMs 108. A downlink attenuator 126 and uplink attenuator 128 are
provided to control the power level of the downlink electrical RF
communications signals 106(1)-106(R) and uplink electrical RF
communications signals 122(1)-122(R), respectively. A power
detector 130 may be provided to detect the power levels of the
downlink electrical RF communications signals 106(1)-106(R) and
uplink electrical RF communications signals 122(1)-122(R) for
setting the power levels and/or calibrating the downlink and uplink
attenuators 126, 128 to provide the desired power levels of these
signals. Examples of setting power levels and/or calibrating
downlinks and uplinks in head end equipment for a distributed
antenna system are provided U.S. Provisional Patent Application
Ser. Nos. 61/230,463 and 61/230,472, both of which are incorporated
herein by reference in their entireties.
Each of the RIMs 102(1)-102(M) includes a 1:Q downlink splitter 132
to split the received downlink electrical RF communications signals
106(1)-106(R) into a plurality of the downlink electrical RF
communications signals 106(1)-106(R) in distinct downlink paths
134(1)-134(Q) to allow sectorization. "Q" represents the number of
possible sectors that can be provided by the head end equipment
104. Splitting the downlink electrical RF communications signals
106(1)-106(R) into a plurality of the downlink paths 134(1)-134(Q)
allows the received downlink electrical RF communications signals
106(1)-106(R) to be allocated to different sectors. Each of the
downlink paths 134(1)-134(Q) includes an isolation block
136(1)-136(Q) coupled to a downlink sector switch 138(1)-138(Q).
Each downlink sector switch 138(1)-138(Q) represents a sector 1-Q
in the head end equipment 104. The downlink sector switches
138(1)-138(Q) control whether a split downlink electrical RF
communications signal 106(1)-106(R) is provided to a given sector
1-Q. Since each downlink sector switch 138(1)-138(Q) represents a
given sector 1-Q, the radio band or bands supported by a given RIM
102 can be allocated to a given sector or sectors based on
activation of the downlink sector switches 138(1)-138(Q).
The outputs of the downlink sector switches 138(1)-138(Q) are
directed to a RIM distribution matrix 140. The RIM distribution
matrix 140 is comprised of RIM interfaces 140(1)-140(Q) that
interface each of the downlink paths 134(1)-134(Q) (i.e. sectors)
in each of the RIMs 102(1)-102(M) to each of the OIMs
108(1)-108(N). In this manner, the downlink sector switches
138(1)-138(Q) activated in the RIMs 102(1)-102(M) define the radio
bands provided for each sector 1-Q. For example, if downlink sector
switches 138(1) and 138(2) are activated for RIM 102(1), the radio
band(s) filtered by the filters 124 for the RIM 102(1) will be
provided on sectors 1 and 2. Thus, any RAUs 112 allocated to
sectors 1 and 2 will receive RF communications signals for the
radio band(s) filtered by the filters 124 for the RIM 102(1) and
will be provided on sectors 1 and 2. If the downlink sector
switches 138(1) and 138(2) are activated, for example, in any other
of the RIMs 102(2)-102(M), the radio band(s) filtered by those RIMs
102(2)-102(M) will also be provided to RAUs 112 allocated to
sectors 1 and 2. In this manner, the radio bands provided in the
available sectors 1-Q can be controlled by controlling the downlink
sector switches 138(1)-138(Q) in the RIMs 102(1)-102(M).
The RIM distribution matrix 140 and the RIM interfaces
140(1)-140(Q) provided therein for each sector 1-Q are coupled to a
complementary OIM distribution matrix 142 in an optical interface
unit (OIU) 143. The OIM distribution matrix 142 is comprised of a
plurality of OIM interface cards 142(1)-142(Q) for each sector. The
OIM interface cards 142(1)-142(Q) interface each of the sectors 1-Q
to each of the OIMs 108(1)-108(N). Thus, the downlink electrical RF
communications signals 106(1)-106(R) allocated to the sectors 1-Q
in the RIMs 102(1)-102(M) are provided to the OIMs 108(1)-108(N) to
be distributed to the RAUs 112 coupled to the OIMs 108(1)-108(N).
Downlink sector switches 144(1)-144(Q) are provided in each OIM
108(1)-108(N) to control which sectors among sectors 1-Q a
particular OIM 108(1)-108(N) will support. Activation of the
downlink sector switches 144(1)-144(Q) controls whether the OIM 108
supports a given sector 1-Q. A sector(s) selected as being
supported by a particular OIM 108 in this embodiment means, in
turn, that the RAUs 112 supported by the OIM 108 are allocated to
the selected sector(s). For example, if three (3) RAUs 112 are
supported by a particular OIM 108, each of these three (3) RAUs 112
will be allocated to the same sectors according to the settings of
the downlink sector switches 144(1)-144(Q) in the OIM 108.
The outputs of the downlink sector switches 144(1)-144(Q) in each
OIM 108(1)-108(N) are coupled to isolations blocks 146(1)-146(Q),
which are coupled to a Q:1 combiner 148. The combiner 148 combines
all of the downlink electrical RF communications signals
106(1)-106(R) for the sectors 1-Q selected for an OIM 108 to
provide optically converted downlink electrical RF communications
signals 106(1)-106(R) for the selected sectors 1-Q as downlink
optical RF communications signals 110(1)-110(R) to the RAUs 112
coupled to the OIM 108. A downlink attenuator 150 is provided in
each OIM 108(1)-108(N) to allow the power level of the downlink
optical RF communications signals 110(1)-110(R) to be controlled
and for calibration purposes. A power detector 152 is included in
each OIM 108(1)-108(N) to detect the power levels of the downlink
optical RF communications signals 110(1)-110(R) to control the
setting of the downlink attenuator 150.
Sectorization can also be provided in the uplink paths of the head
end equipment 104 to direct uplink optical RF communication signals
118 from the RAUs 112 to the appropriate RIMs 102(1)-102(M) based
on the sectors allocated to the RAUs 112 discussed above. In this
regard, with continuing reference to FIG. 6, each OIM 108(1)-108(N)
includes an uplink attenuator 154 to control the power level of the
uplink optical RF communication signals 118(1)-118(R) received from
the RAUs 112 supported by the OIM 108(1)-108(N). A 1:Q optical
splitter 156 is provided to split the uplink optical RF
communication signals 118(1)-118(R) into separate uplink paths
158(1)-158(Q) for each sector 1-Q. In this manner, the uplink paths
158(1)-158(Q), after being isolated by isolation blocks
160(1)-160(Q), can be controlled by uplink sector switches
162(1)-162(Q) provided for each sector 1-Q. Uplink sector switches
162(1)-162(Q) control providing each of the split plurality of
uplink optical RF communications signals 118(1)-118(R) to the same
sectors 1-Q selected for the OIM 108 according to the activation of
the downlink sector switches 144(1)-144(Q). In this manner, the
uplink electrical RF communications signals 120(1)-120(R) will be
provided to the appropriate RIMs 102(1)-102(M) through the
distribution matrices 140, 142.
The RIMs 102(1)-102(M) each include uplink sector switches
164(1)-164(Q) for each sector 1-Q to allow the uplink electrical RF
communications signals 120(1)-120(R) from the RAUs 112 allocated to
sectors to be passed through the RIMs 102(1)-102(M) allocated to
the corresponding sectors. The settings of the uplink sector
switches 164(1)-164(Q) for a particular RIM 102 will be the same as
the downlink sector switches 138(1)-138(Q) for the RIM 102. The
uplink electrical RF communications signals 120(1)-120(R) that are
allowed to pass via selection of the uplink sector switches
164(1)-164(Q) are isolated via isolation blocks 166(1)-166(Q) and
are passed to a Q:1 combiner 168. The Q:1 combiner 168 combines the
uplink electrical RF communications signals 120(1)-120(R) from the
RAUs 112 allocated to the same sectors as selected for the RIM 102
according to the uplink sector switches 164(1)-164(Q) to be
provided as uplink electrical RF communications signals
122(1)-122(R) from the RIMs 102(1)-102(M).
Sectors can be configured for the RIMs 102(1)-102(M) and OIMs
108(1)-108(N) in any number of manners. For instance, the sector
switches 138(1)-138(Q), 144(1)-144(Q), 162(1)-162(Q), 164(1)-164(Q)
can be provided by manually actuated switches provided in the head
end equipment 104. Alternatively, the sector switches
138(1)-138(Q), 144(1)-144(Q), 162(1)-162(Q), 164(1)-164(Q) can be
programmed or changed via control other than manual control. For
example, the RIMs 102(1)-102(M) may each include a controller 170,
such as a microcontroller or microprocessor for example as
illustrated in FIG. 6, that is configured to control the RIM sector
switches 138(1)-138(Q), 164(1)-164(Q). Similarly, the OIMs
108(1)-108(N) may each include a controller 172, such as a
microcontroller or microprocessor 170 for example, that is
configured to control the OIM sector switches 144(1)-144(Q),
162(1)-162(Q). The controllers 170, 172 may be communicatively
coupled to an interface, such as a user interface (UI), including a
graphical user interface (GUI), that allows a user to configure the
settings of the sector switches 138(1)-138(Q), 144(1)-144(Q),
162(1)-162(Q), 164(1)-164(Q) to provide the desired sectorization
of the RAUs 112. Examples of providing access to the head end
equipment 104 to control settings of components in the head end
equipment 104 are provided in U.S. Provisional Patent Application
Ser. No. 61/230,472 incorporated herein by reference in its
entirety.
With continuing reference to FIG. 6, the sectorization settings may
be stored in memory 174, 176 associated with each of the RIMs
102(1)-102(M) and OIMs 108(1)-108(N), respectively. The controllers
170, 172 may be configured to alter and/or update the
sectorizations for the RIMs 102(1)-102(M) and OIMs 108(1)-108(N) by
setting sectorization settings in the memory 174, 176. The
controllers 170, 172 can then consul the memory 174, 176 to apply
configured or programmed settings to the sector switches
138(1)-138(Q), 144(1)-144(Q), 162(1)-162(Q), 164(1)-164(Q) to
provide the desired sectorization in the distributed antenna system
100. In this regard, FIG. 7 illustrates an exemplary RIM
sectorization table 180 that can be provided in the memory 174 in
the RIMs 102(1)-102(M) to store default and/or configured
sectorization settings for the sector switches 138(1)-138(Q),
164(1)-164(Q) in the RIMs 102(1)-102(M). A similar sectorization
table could be provided in the memory 176 of the OIMs 108(1)-108(N)
to store default and/or configured sectorization settings for the
sector switches 144(1)-144(Q), 162(1)-162(Q) in the RIMs
102(1)-102(M).
With continuing reference to FIG. 7, the RIM sectorization table
180 in this example is a two-dimensional table to allow for
sectorization settings to be provided for each RIM 102(1)-102(M)
configured in the head end equipment 104. The radio band filtered
and allowed to pass through each RIM 102(1)-102(M) is provided in a
radio band column 182 in the RIM sectorization table 180. The pass
through radio band for the RIMs 102 may be a static setting, or if
the filters 124 in the RIMs 102(1)-102(M) are configurable, the
pass through radio band stored in the radio band column 182 may be
configurable.
For each RIM 102(1)-102(M) and radio band 182 configuration,
sectorization settings 184 are provided in the RIM sectorization
table 180. In this example, if the pass through radio band
configured for a given RIM 102(1)-102(M) is configured to be
provided for a given sector or sectors, a "Pband" setting is
provided in the sectors row 186 for the RIM 102 under the sectors
to be activated, as illustrated in FIG. 7. A gain setting may also
be provided, as illustrated in the RIM sectorization table 180. For
example, RIM 102(M) is assigned to Sector 1 186(1) with a gain
adjustment of -FdB, wherein F=10 Log [n] dB, where n is the active
number of services provided on the same radio band. For example if
three (3) services are deployed in the same radio band per sector,
the gain adjustment could be Pband -5 dB per service.
The appropriate sector switches 138(1)-138(Q), 164(1)-164(Q) are
activated according to the sector settings for the RIMs
102(1)-102(M) in the sectors row 186. For example, for the RIM
102(3) in the RIM sectorization table 180, sector switches 138(1),
164(1) will be activated with the other sector switches
138(2)-138(Q), 164(2)-164(Q) deactivated for the RIM 102(3) to pass
through radio band "Band 1" to be included Sector 1 and provided to
RAUs 112 allocated to Sector 1 in the OIMs 108(1)-108(N). Further,
an attenuation level may be provided for a sector setting that is
applied to the downlink attenuator 126 in the RIMs
102(1)-102(M).
Other configurations of allocating sectors to OIMs may be provided.
For example, it may be desired to allocate additional RAUs 112 to a
sector(s) that can be supported in the head end equipment 104 in
FIGS. 5 and 6 as an example. For example, if the optical interface
component (OIU) 143 supporting the OIMs 108(1)-108(N) in FIG. 6 is
configured to support thirty-six (36) RAUs 112(1)-112(P), and it is
desired to allocate additional RAUs to a sector or sectors in the
head end equipment 104, such would not be possible with the example
head end equipment 104 in FIG. 6. In this regard, FIG. 8 is a
schematic diagram of the exemplary head end equipment 104 in FIGS.
5 and 6, but configured with one or more expansion ports 190 to
allow additional OIUs 143(2)-143(T) to be allocated to a sector or
sectors provided by the head end equipment 104. The notation "T"
indicates that any number of additional OIUs may be provided.
As illustrated in FIG. 8, expansion ports 190(1)-190(Q) are
provided in the head end equipment 104 to receive RF communications
signals assigned to a sector(s) in the RIMs 102(1)-102(M) provided
in the head end equipment 104. Additional OIUs 143(2)-143(T) each
supporting the OIMs 108(1)-108(N) that each support the RAUs
112(1)-112(P) can be coupled to the expansion ports 190(1)-190(Q).
In this manner, the additional RAUs 112(1)-112(P) supported by the
OIMs 108(1)-108(M) in the OIUs 143(2)-143(T) can be allocated to
sectors provided by the head end equipment 104. For example, as
illustrated in FIG. 8, an OIM distribution matrix 142(2) provided
in the OIU 143(2) is coupled to the expansion port 190(1) for
Sector 1 so that OIMs 108(1)-108(N) in the OIC 143(2) can be
configured to receive RF communications signals from the RIMs
102(1)-102(M) in the head end equipment 104 configured for Sector
1. The sector switches (not shown) in the OIMs 108(1)-108(N) in the
OIU 143(2) can be set to allocate RAUs 112(1)-112(P) supported by
the OIU 143(2) to Sector 1, if desired. Note that FIG. 8 only
illustrates the expansion ports 190 being provided in the downlink
of the head end equipment 104, but expansion ports can also be
provided in the uplink of the head end equipment 104 as well.
The RAUs 112(1)-112(P) supported by the OIU 143(2) in FIG. 8 can
only be allocated to one sector provided in the head end equipment
104, which is Sector 1 in this example, because the OIU 143(2) is
not coupled to the other expansion ports 190(2)-190(Q) in the head
end equipment 104. However, in FIG. 9, the OIU 143(2) is configured
to be coupled to each of the sectors provided by the head end
equipment 104. In this manner, the RAUs 112(1)-112(P) supported by
the OIMs 108(1)-108(N) in the OIU 143(2) can be allocated to any of
the sectors provided by the head end equipment 104. Thus, the OIU
143(2) is configured to provide multiple sectors to the RAUs
112(1)-112(P) supported by the OIMs 108(1)-108(N) in the OIU
143(2). Note that FIG. 9 only illustrates the expansion ports 190
being provided in the downlink of the head end equipment 104, but
expansion ports can also be provided in the uplink of the head end
equipment 104 as well.
The head end equipment 104 can also be configured to share
components with multiple carriers. For example, a distributed
antenna system may include multiple carriers. Further, an
installation of a distributed antenna system with a first carrier
may be later configured to support other carriers. In this regard,
FIG. 10 illustrates the head end equipment 104 where two (2)
carriers (CARRIER 1 and CARRIER 2) provide their own respective
downlink electrical RF communications signals 106(1)-106(R) to
radio interfaces 200(1), 200(2), respectively, having their own
dedicated RIMs 102(1)-102(M). An external radio distribution matrix
204 is provided that allows each of the RIMs 102(1)-102(M) provided
in the radio interfaces 200(1), 200(2) to share the same OIUs
143(1)-143(T) and supported RAUs 112(1)-112(P). In this manner,
additional OIUs 143 and associated cabling are not required for
each carrier to route RF communications signals to the shared RAUs
112(1)-112(P). RAUs 112(1)-112(P) can be allocated to sectors that
include RF communications signals from both carriers.
The head end equipment 104 can also be configured to provide
additional sectors as illustrated in FIG. 11. For example, if the
head end equipment 104 in the previous figures supports three (3)
sectors, additional radio interfaces 200(1)-200(S) can be provided,
as illustrated in FIG. 11, to provide additional sectors in a
modular fashion. The notation "S" indicates that any number of
radio interfaces may be provided. The external radio distribution
matrix 204 routes the expanded sectors to the OIUs 143(1)-143(T)
such that the RAUs 112(1)-112(P) supported by any of the OIUs
143(1)-143(T) can be allocated to any of the expanded number of
sectors provided by the radio interfaces 200(1)-200(S).
FIG. 12 is a schematic diagram of an exemplary head end equipment
104 provided in the distributed antenna system 100 supporting
sectorization and multiple-input, multiple-output (MIMO) processing
in a distributed antenna system. MIMO can provide increased bit
rates or beam forming for signal-to-noise ratios (SNRs) through
improved spectrum efficiency and/or wireless distance improvement.
In this embodiment, MIMO is achieved by utilizing multiple spatial
layers (e.g., up to four (4) layers by 3GPP standards) to a given
client device.
FIG. 12 illustrates the head end equipment 104 illustrated in FIG.
5 and previously discussed configured to support 2.times.2 MIMO
with two (2) sectors. Common elements are illustrated in FIG. 12
with common element numbers and will not be redescribed. A
2.times.2 MIMO scheme can be provided for the distributed antenna
system 100 when two (2) RAUs 112(1), 112(2) are co-located to
create two (2) spatial streams using the same frequency radio band
as illustrated in FIG. 12, but any other MIMO configuration desired
is also possible.
With continuing reference to FIG. 12, the first and second sectors
in this example are associated with first and second radio streams
210(1), 210(2), respectively. The first and second radio streams
210(1), 210(2) each contain four (4) radio bands in this example.
The RAUs 112(1), 112(2) are assigned to sectors such that all four
(4) of the radio bands in the radio streams 210(1), 210(2) are
delivered to two (2) RAUs 112(1), 112(2) deployed at the same
location in this example. In this example, RAU 112(1) is assigned
to a first sector that includes the four (4) radio bands in the
first radio stream 210(1). RAU 112(2) is also assigned to the same
sector as assigned to the RAU 112(1). Thus, radio communications to
the RAUs can support MIMO communications across the four (4) radio
bands provided in the radio streams 210(1), 210(2). The radio bands
supported in MIMO communications by the RAUs 112(1), 112(2) can be
changed by reassigning the RAUs 112(1), 112(2) to different sectors
or reconfiguring existing sectors to which the RAUs 112(1), 112(2)
are assigned.
Those of skill in the art would further appreciate that the various
illustrative logical blocks, modules, circuits, and algorithms
described in connection with the embodiments disclosed herein may
be implemented as electronic hardware, instructions stored in
memory or in another computer-readable medium and executed by a
processor or other processing device, or combinations of both. The
components of the distributed antenna systems described herein may
be employed in any circuit, hardware component, integrated circuit
(IC), or IC chip, as examples. Memory disclosed herein may be any
type and size of memory and may be configured to store any type of
information desired. To clearly illustrate this interchangeability,
various illustrative components, blocks, modules, circuits, and
steps have been described above generally in terms of their
functionality. How such functionality is implemented depends upon
the particular application, design choices, and/or design
constraints imposed on the overall system. Skilled artisans may
implement the described functionality in varying ways for each
particular application, but such implementation decisions should
not be interpreted as causing a departure from the scope of the
present invention.
The various illustrative logical blocks, modules, and circuits
described in connection with the embodiments disclosed herein may
be implemented or performed with a processor, a Digital Signal
Processor (DSP), an Application Specific Integrated Circuit (ASIC),
a Field Programmable Gate Array (FPGA) or other programmable logic
device, discrete gate or transistor logic, discrete hardware
components, or any combination thereof designed to perform the
functions described herein. A controller may be a processor. A
processor may be a microprocessor, but in the alternative, the
processor may be any conventional processor, controller,
microcontroller, or state machine. A processor may also be
implemented as a combination of computing devices, e.g., a
combination of a DSP and a microprocessor, a plurality of
microprocessors, one or more microprocessors in conjunction with a
DSP core, or any other such configuration.
The embodiments disclosed herein may be embodied in hardware and in
instructions that are stored in hardware, and may reside, for
example, in Random Access Memory (RAM), flash memory, Read Only
Memory (ROM), Electrically Programmable ROM (EPROM), Electrically
Erasable Programmable ROM (EEPROM), registers, hard disk, a
removable disk, a CD-ROM, or any other form of computer readable
medium known in the art. An exemplary storage medium is coupled to
the processor such that the processor can read information from,
and write information to, the storage medium. In the alternative,
the storage medium may be integral to the processor. The processor
and the storage medium may reside in an ASIC. The ASIC may reside
in a remote station. In the alternative, the processor and the
storage medium may reside as discrete components in a remote
station, base station, or server.
It is also noted that the operational steps described in any of the
exemplary embodiments herein are described to provide examples and
discussion. The operations described may be performed in numerous
different sequences other than the illustrated sequences.
Furthermore, operations described in a single operational step may
actually be performed in a number of different steps. Additionally,
one or more operational steps discussed in the exemplary
embodiments may be combined. It is to be understood that the
operational steps illustrated in the flow chart diagrams may be
subject to numerous different modifications as will be readily
apparent to one of skill in the art. Those of skill in the art
would also understand that information and signals may be
represented using any of a variety of different technologies and
techniques. For example, data, instructions, commands, information,
signals, bits, symbols, and chips that may be referenced throughout
the above description may be represented by voltages, currents,
electromagnetic waves, magnetic fields or particles, optical fields
or particles, or any combination thereof.
Further, as used herein, it is intended that terms "fiber optic
cables" and/or "optical fibers" include all types of single mode
and multi-mode light waveguides, including one or more optical
fibers that may be upcoated, colored, buffered, ribbonized and/or
have other organizing or protective structure in a cable such as
one or more tubes, strength members, jackets or the like. The
optical fibers disclosed herein can be single mode or multi-mode
optical fibers. Likewise, other types of suitable optical fibers
include bend-insensitive optical fibers, or any other expedient of
a medium for transmitting light signals. An example of a
bend-insensitive, or bend resistant, optical fiber is
ClearCurve.RTM. Multimode fiber commercially available from Corning
Incorporated. Suitable fibers of this type are disclosed, for
example, in U.S. Patent Application Publication Nos. 2008/0166094
and 2009/0169163, the disclosures of which are incorporated herein
by reference in their entireties.
Many modifications and other embodiments of the embodiments set
forth herein will come to mind to one skilled in the art to which
the embodiments pertain having the benefit of the teachings
presented in the foregoing descriptions and the associated
drawings. Therefore, it is to be understood that the description
and claims are not to be limited to the specific embodiments
disclosed and that modifications and other embodiments are intended
to be included within the scope of the appended claims. It is
intended that the embodiments cover the modifications and
variations of the embodiments provided they come within the scope
of the appended claims and their equivalents. Although specific
terms are employed herein, they are used in a generic and
descriptive sense only and not for purposes of limitation.
* * * * *